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Miura K, Morishige JI, Abe J, Xu P, Shi Y, Jing Z, Nagata N, Miyazaki R, Sakane N, Mieda M, Ono M, Maida Y, Fujiwara T, Fujiwara H, Ando H. Imeglimin profoundly affects the circadian clock in mouse embryonic fibroblasts. J Pharmacol Sci 2023; 153:215-220. [PMID: 37973219 DOI: 10.1016/j.jphs.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/04/2023] [Accepted: 10/10/2023] [Indexed: 11/19/2023] Open
Abstract
OBJECTIVE Imeglimin is a novel antidiabetic drug structurally related to metformin. Metformin has been shown to modulate the circadian clock in rat fibroblasts. Accordingly, in the present study, we aimed to determine whether imeglimin can impact the circadian oscillator in mouse embryonic fibroblasts (MEFs). METHODS MEFs carrying a Bmal1-Emerald luciferase (Bmal1-ELuc) reporter were exposed to imeglimin (0.1 or 1 mM), metformin (0.1 or 1 mM), a nicotinamide phosphoribosyltransferase inhibitor FK866, and/or vehicle. Subsequently, Bmal1-ELuc expression and clock gene mRNA expression levels were measured at 10-min intervals for 55 h and 4-h intervals for 32 h, respectively. RESULTS Imeglimin significantly prolonged the period (from 26.3 to 30.0 h at 0.1 mM) and dose-dependently increased the amplitude (9.6-fold at 1 mM) of the Bmal1-ELuc expression rhythm; however, metformin exhibited minimal effects on these parameters. Moreover, imeglimin notably impacted the rhythmic mRNA expression of clock genes (Bmal1, Per1, and Cry1). The concurrent addition of FK866 partly inhibited the effects of imeglimin on both Bmal1-ELuc expression and clock gene mRNA expression. CONCLUSION Collectively, these results reveal that imeglimin profoundly affects the circadian clock in MEFs. Further studies are needed to evaluate whether imeglimin treatment could exert similar effects in vivo.
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Affiliation(s)
- Kotomi Miura
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Jun-Ichi Morishige
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Jotaro Abe
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Pingping Xu
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Yifan Shi
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Zheng Jing
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Naoto Nagata
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Ryo Miyazaki
- Faculty of Human Sciences, Shimane University, Matsue, Japan
| | - Naoki Sakane
- Division of Preventive Medicine, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto, Japan
| | - Michihiro Mieda
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Masanori Ono
- Department of Obstetrics and Gynecology, Tokyo Medical University, Tokyo, Japan
| | - Yoshiko Maida
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Tomoko Fujiwara
- Department of Human Life Environments, Kyoto Notre Dame University, Kyoto, Japan
| | - Hiroshi Fujiwara
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Hitoshi Ando
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.
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Tabei Y, Abe H, Suzuki S, Takeda N, Arai JI, Nakajima Y. Sedanolide Activates KEAP1-NRF2 Pathway and Ameliorates Hydrogen Peroxide-Induced Apoptotic Cell Death. Int J Mol Sci 2023; 24:16532. [PMID: 38003720 PMCID: PMC10671709 DOI: 10.3390/ijms242216532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023] Open
Abstract
Sedanolide is a bioactive compound with anti-inflammatory and antitumor activities. Although it has been recently suggested that sedanolide activates the nuclear factor E2-related factor 2 (NRF2) pathway, there is little research on its effects on cellular resistance to oxidative stress. The objective of the present study was to investigate the function of sedanolide in suppressing hydrogen peroxide (H2O2)-induced oxidative damage and the underlying molecular mechanisms in human hepatoblastoma cell line HepG2 cells. We found that sedanolide activated the antioxidant response element (ARE)-dependent transcription mediated by the nuclear translocation of NRF2. Pathway enrichment analysis of RNA sequencing data revealed that sedanolide upregulated the transcription of antioxidant enzymes involved in the NRF2 pathway and glutathione metabolism. Then, we further investigated whether sedanolide exerts cytoprotective effects against H2O2-induced cell death. We showed that sedanolide significantly attenuated cytosolic and mitochondrial reactive oxygen species (ROS) generation induced by exposure to H2O2. Furthermore, we demonstrated that pretreatment with sedanolide conferred a significant cytoprotective effect against H2O2-induced cell death probably due to preventing the decrease in the mitochondrial membrane potential and the increase in caspase-3/7 activity. Our study demonstrated that sedanolide enhanced cellular resistance to oxidative damage via the activation of the Kelch-like ECH-associated protein 1 (KEAP1)-NRF2 pathway.
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Affiliation(s)
- Yosuke Tabei
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu 761-0395, Kagawa, Japan; (Y.T.); (H.A.); (S.S.)
| | - Hiroko Abe
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu 761-0395, Kagawa, Japan; (Y.T.); (H.A.); (S.S.)
| | - Shingo Suzuki
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu 761-0395, Kagawa, Japan; (Y.T.); (H.A.); (S.S.)
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho 761-0793, Kagawa, Japan
| | - Nobuaki Takeda
- Technology and Innovation Center, Daikin Industries, Ltd., 1-1 Nishi-Hitotsuya, Settsu 566-8585, Osaka, Japan; (N.T.); (J.-i.A.)
| | - Jun-ichiro Arai
- Technology and Innovation Center, Daikin Industries, Ltd., 1-1 Nishi-Hitotsuya, Settsu 566-8585, Osaka, Japan; (N.T.); (J.-i.A.)
| | - Yoshihiro Nakajima
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu 761-0395, Kagawa, Japan; (Y.T.); (H.A.); (S.S.)
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3
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Kobayashi Y, Akagi Y, Tsubaki K, Shimoda E, Kikuchi T, Endo N, Ichiyanagi T, Nakagiri A, Nishida T, Ishihara A. Identification of Cyclocybe erebia metabolites that affect the circadian rhythm of Eluc expression under control of Bmal1 promoter in mouse fibroblast cells. J Biosci Bioeng 2023; 136:278-286. [PMID: 37550133 DOI: 10.1016/j.jbiosc.2023.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 06/15/2023] [Accepted: 06/29/2023] [Indexed: 08/09/2023]
Abstract
Pharmacological intervention of circadian rhythms is a potentially useful approach for ameliorating various health problems caused by disturbed circadian rhythms including sleep disorder and metabolic diseases. To find compounds that affect circadian rhythms, we screened mushroom extracts using mouse cells expressing the luciferase gene under the control of the mouse Bmal1 promoter. The culture filtrate extract from the basidiomycete Cyclocybe erebia enhanced the oscillation of bioluminescence caused by the expression of the luciferase gene and prolonged the period of bioluminescence. Bioassay-guided fractionation of the extract resulted in purification of compounds 1 and 2. Spectroscopic analyses along with single-crystal X-ray diffraction analysis, revealed that these compounds were diterpenoids with a unique skeleton and a fused ring system comprising 3-, 7-, and 5-membered rings. Compounds 1 and 2 were named cyclocircadins A and B, respectively. These findings suggested that natural diterpenoids could be a source of compounds with the activity affecting circadian rhythms.
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Affiliation(s)
- Yusei Kobayashi
- The United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyamacho-minami, Tottori 680-8553, Japan; GPC Laboratory, Tottori Bio-Frontier, 86 Nishi-cho, Yonago, Tottori 683-0826, Japan
| | - Yasunori Akagi
- GPC Laboratory, Tottori Bio-Frontier, 86 Nishi-cho, Yonago, Tottori 683-0826, Japan
| | - Kaori Tsubaki
- GPC Laboratory, Tottori Bio-Frontier, 86 Nishi-cho, Yonago, Tottori 683-0826, Japan
| | - Emiko Shimoda
- Fungus/Mushroom Resource and Research Center, Faculty of Agriculture, Tottori University, 4-101, Koyamacho-minami, Tottori 680-8553, Japan
| | - Takashi Kikuchi
- Rigaku Corporation, 3-9-12 Matsubara-cho, Akishima-shi, Tokyo 196-8666, Japan
| | - Naoki Endo
- Fungus/Mushroom Resource and Research Center, Faculty of Agriculture, Tottori University, 4-101, Koyamacho-minami, Tottori 680-8553, Japan
| | - Tsuyoshi Ichiyanagi
- Fungus/Mushroom Resource and Research Center, Faculty of Agriculture, Tottori University, 4-101, Koyamacho-minami, Tottori 680-8553, Japan
| | - Akira Nakagiri
- Fungus/Mushroom Resource and Research Center, Faculty of Agriculture, Tottori University, 4-101, Koyamacho-minami, Tottori 680-8553, Japan
| | - Tadashi Nishida
- GPC Laboratory, Tottori Bio-Frontier, 86 Nishi-cho, Yonago, Tottori 683-0826, Japan
| | - Atsushi Ishihara
- Fungus/Mushroom Resource and Research Center, Faculty of Agriculture, Tottori University, 4-101, Koyamacho-minami, Tottori 680-8553, Japan.
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Takeda H, Nakajima Y, Yamaguchi T, Watanabe I, Miyoshi S, Nagashio K, Sekine H, Motohashi H, Yano H, Tanaka J. The anti-inflammatory and anti-oxidative effect of a classical hypnotic bromovalerylurea mediated by the activation of NRF2. J Biochem 2023; 174:131-142. [PMID: 37039781 PMCID: PMC10372716 DOI: 10.1093/jb/mvad030] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 03/14/2023] [Accepted: 04/05/2023] [Indexed: 04/12/2023] Open
Abstract
The Kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor 2 (KEAP1-NRF2) system plays a central role in redox homeostasis and inflammation control. Oxidative stress or electrophilic compounds promote NRF2 stabilization and transcriptional activity by negatively regulating its inhibitor, KEAP1. We have previously reported that bromovalerylurea (BU), originally developed as a hypnotic, exerts anti-inflammatory effects in various inflammatory disease models. However, the molecular mechanism underlying its effect remains uncertain. Herein, we found that by real-time multicolor luciferase assay using stable luciferase red3 (SLR3) and green-emitting emerald luciferase (ELuc), BU potentiates NRF2-dependent transcription in the human hepatoblastoma cell line HepG2 cells, which lasted for more than 60 h. Further analysis revealed that BU promotes NRF2 accumulation and the transcription of its downstream cytoprotective genes in the HepG2 and the murine microglial cell line BV2. Keap1 knockdown did not further enhance NRF2 activity, suggesting that BU upregulates NRF2 by targeting KEAP1. Knockdown of Nfe2l2 in BV2 cells diminished the suppressive effects of BU on the production of pro-inflammatory mediators, like nitric oxide (NO) and its synthase NOS2, indicating the involvement of NRF2 in the anti-inflammatory effects of BU. These data collectively suggest that BU could be repurposed as a novel NRF2 activator to control inflammation and oxidative stress.
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Key Words
- Abbreviations: ARE, antioxidant responsive element; BU, bromovalerylurea; CCL2, C-C motif chemokine 2; DMF, dimethyl fumarate; GCLC, glutamate–cysteine ligase catalytic subunit; GCLM, glutamate–cysteine ligase modifier subunit; GSS, glutathione synthetase; GSH, glutathione; Hmox-1, heme oxygenase-1; IL-1β, interluekin-1β; IL-6, interluekin-6; JAK, Janus kinase; KEAP1, Kelch-like ECH-associated protein; NO, nitric oxide; NOS2, NO synthase 2; NRE, NF-κB responsive element; NQO-1, NAD(P)H quinone dehydrogenase; NRF2, nuclear factor erythroid 2-related factor 2/nuclear factor erythroid-derived 2-like 2; TXNRD, thioredoxin–disulfide reductase; ROS, reactive oxygen species
- KEAP1–NRF2
- anti-inflammation
- anti-oxidant oxygen
- bromovalerylurea
- drug action toxins/drugs/xenobiotics
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Affiliation(s)
- Haruna Takeda
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, 454, Shitsukawa, Toon, Ehime, 791-0295, Japan
- Department of Gene Expression Regulation, Institute of Development, Aging and Cancer, Tohoku University, 4-1, Seiryo-cho, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Yoshihiro Nakajima
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2 217-14, Hayashi-cho, Takamatsu, Kagawa, 761-0301, Japan
| | - Teruaki Yamaguchi
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, 454, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Itaru Watanabe
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, 454, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Shoko Miyoshi
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, 454, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Kodai Nagashio
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, 454, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Hiroki Sekine
- Department of Gene Expression Regulation, Institute of Development, Aging and Cancer, Tohoku University, 4-1, Seiryo-cho, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Hozumi Motohashi
- Department of Gene Expression Regulation, Institute of Development, Aging and Cancer, Tohoku University, 4-1, Seiryo-cho, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Hajime Yano
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, 454, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Junya Tanaka
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, 454, Shitsukawa, Toon, Ehime, 791-0295, Japan
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5
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Fawad JA, Luzader DH, Hanson GF, Moutinho TJ, McKinney CA, Mitchell PG, Brown-Steinke K, Kumar A, Park M, Lee S, Bolick DT, Medlock GL, Zhao JY, Rosselot AE, Chou CJ, Eshleman EM, Alenghat T, Hong CI, Papin JA, Moore SR. Histone Deacetylase Inhibition by Gut Microbe-Generated Short-Chain Fatty Acids Entrains Intestinal Epithelial Circadian Rhythms. Gastroenterology 2022; 163:1377-1390.e11. [PMID: 35934064 DOI: 10.1053/j.gastro.2022.07.051] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/13/2022] [Accepted: 07/14/2022] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS The circadian clock orchestrates ∼24-hour oscillations of gastrointestinal epithelial structure and function that drive diurnal rhythms in gut microbiota. Here, we use experimental and computational approaches in intestinal organoids to reveal reciprocal effects of gut microbial metabolites on epithelial timekeeping by an epigenetic mechanism. METHODS We cultured enteroids in media supplemented with sterile supernatants from the altered Schaedler Flora (ASF), a defined murine microbiota. Circadian oscillations of bioluminescent PER2 and Bmal1 were measured in the presence or absence of individual ASF supernatants. Separately, we applied machine learning to ASF metabolomics to identify phase-shifting metabolites. RESULTS Sterile filtrates from 3 of 7 ASF species (ASF360 Lactobacillus intestinalis, ASF361 Ligilactobacillus murinus, and ASF502 Clostridium species) induced minimal alterations in circadian rhythms, whereas filtrates from 4 ASF species (ASF356 Clostridium species, ASF492 Eubacterium plexicaudatum, ASF500 Pseudoflavonifactor species, and ASF519 Parabacteroides goldsteinii) induced profound, concentration-dependent phase shifts. Random forest classification identified short-chain fatty acid (SCFA) (butyrate, propionate, acetate, and isovalerate) production as a discriminating feature of ASF "shifters." Experiments with SCFAs confirmed machine learning predictions, with a median phase shift of 6.2 hours in murine enteroids. Pharmacologic or botanical histone deacetylase (HDAC) inhibitors yielded similar findings. Further, mithramycin A, an inhibitor of HDAC inhibition, reduced SCFA-induced phase shifts by 20% (P < .05) and conditional knockout of HDAC3 in enteroids abrogated butyrate effects on Per2 expression. Key findings were reproducible in human Bmal1-luciferase enteroids, colonoids, and Per2-luciferase Caco-2 cells. CONCLUSIONS Gut microbe-generated SCFAs entrain intestinal epithelial circadian rhythms by an HDACi-dependent mechanism, with critical implications for understanding microbial and circadian network regulation of intestinal epithelial homeostasis.
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Affiliation(s)
- Jibraan A Fawad
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, Virginia
| | - Deborah H Luzader
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, Virginia
| | - Gabriel F Hanson
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, Virginia
| | - Thomas J Moutinho
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Craig A McKinney
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, Virginia
| | - Paul G Mitchell
- University of Virginia School of Medicine, Charlottesville, Virginia
| | - Kathleen Brown-Steinke
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, Virginia
| | - Ajay Kumar
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, Virginia
| | - Miri Park
- Department of Pharmacology & Systems Physiology, University of Cincinnati, Cincinnati, Ohio
| | - Suengwon Lee
- Department of Pharmacology & Systems Physiology, University of Cincinnati, Cincinnati, Ohio
| | - David T Bolick
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, Virginia
| | - Greg L Medlock
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, Virginia
| | - Jesse Y Zhao
- University of Virginia School of Medicine, Charlottesville, Virginia
| | - Andrew E Rosselot
- Department of Pharmacology & Systems Physiology, University of Cincinnati, Cincinnati, Ohio
| | - C James Chou
- College of Pharmacy, Medical University of South Carolina, Charleston, South Carolina
| | - Emily M Eshleman
- Division of Immunobiology, Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center and the University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Theresa Alenghat
- Division of Immunobiology, Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center and the University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Christian I Hong
- Department of Pharmacology & Systems Physiology, University of Cincinnati, Cincinnati, Ohio
| | - Jason A Papin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Sean R Moore
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, Virginia.
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Tomita T, Kawano Y, Kassai M, Onda H, Nakajima Y, Miyazaki K. Hydroxy-β-sanshool isolated from Zanthoxylum piperitum (Japanese pepper) shortens the period of the circadian clock. Food Funct 2022; 13:9407-9418. [PMID: 35960176 DOI: 10.1039/d2fo01036d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We showed that an ethanol extract from Zanthoxylum piperitum can shorten the circadian rhythm at the cellular level and that this activity was due to hydroxy-β-sanshool, a secondary metabolite in this plant. An ethanol extract of Z. piperitum was repeatedly fractionated using solid phase extraction and reverse-phase HPLC, then the circadian rhythms of cells to which the fractions were loaded were monitored using real-time reporter gene assays. We purified one HPLC peak and identified it as hydroxy-β-sanshool using liquid chromatography (LC)-precision-mass spectrometry (MS). This compound shortened the period of Bmal1 and Per2 at the cellular level. Incubation cells for 24 h with hydroxy-β-sanshool resulted in upregulated Per2 promoter activity. Hydroxy-β-sanshool also dose-dependently upregulated expression of the clock genes Bmal1, Per1, Per2 and Cry1 and the clock-controlled oxidative stress responsive genes Gpx1and Sod2.
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Affiliation(s)
- Tatsunosuke Tomita
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba 305-8566, Japan.
| | - Yasuhiro Kawano
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba 305-8566, Japan.
| | - Masahiro Kassai
- S&B Foods Inc., #605 MITSUI LINK-Lab Shinkiba1 Shinkiba 2-3-8, Koto-ku, Tokyo 136-0082, Japan
| | - Hiroyuki Onda
- S&B Foods Inc., #605 MITSUI LINK-Lab Shinkiba1 Shinkiba 2-3-8, Koto-ku, Tokyo 136-0082, Japan
| | - Yoshihiro Nakajima
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Hayashicho 2217-14, Takamatsu, 761-0395, Japan
| | - Koyomi Miyazaki
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba 305-8566, Japan.
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Parasram K, Bachetti D, Carmona-Alcocer V, Karpowicz P. Fluorescent Reporters for Studying Circadian Rhythms in Drosophila melanogaster. Methods Mol Biol 2022; 2482:353-371. [PMID: 35610439 DOI: 10.1007/978-1-0716-2249-0_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Circadian rhythms are daily oscillations in physiology and gene expression that are governed by a molecular feedback loop known as the circadian clock. In Drosophila melanogaster, the core clock consists of transcription factors clock (Clk) and cycle (cyc) which form protein heterodimers that activate transcription of their repressors, period (per) and timeless (tim). Once produced, protein heterodimers of per/tim repress Clk/cyc activity. One cycle of activation and repression takes approximately ("circa") 24-h ("diem") and repeats even in the absence of external stimuli. The circadian clock is active in many cells throughout the body; however, tracking it dynamically represents a challenge. Traditional fluorescent reporters are slowly degraded and consequently cannot be used to assess dynamic temporal changes exhibited by the circadian clock. The use of rapidly degraded fluorescent protein reporters containing destabilized GFP (dGFP) that report transcriptional activity in vivo at a single-cell level with ~1-h temporal resolution can circumvent this problem. Here we describe the use of circadian clock reporter strains of Drosophila melanogaster, ClockPER and ClockTIM, to track clock transcriptional activity using the intestine as a tissue of interest. These methods may be extended to other tissues in the body.
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Affiliation(s)
- Kathyani Parasram
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
| | - Daniela Bachetti
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
| | | | - Phillip Karpowicz
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada.
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Huang S, Lu Q, Choi MH, Zhang X, Kim JY. Applying real-time monitoring of circadian oscillations in adult mouse brain slices to study communications between brain regions. STAR Protoc 2021; 2:100416. [PMID: 33870223 PMCID: PMC8044690 DOI: 10.1016/j.xpro.2021.100416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
This protocol combines a protective cutting method to prepare various brain slices from adult mice and real-time monitoring of circadian oscillations to measure circadian rhythmicity in various brain slices. This protocol can be applied to studies of how brain damages affect local circadian clocks and subsequent circadian variations in nearby areas. Further functional analyses with in vivo systems will determine whether these circadian variations are detrimental or beneficial to the brain. For complete details on the use and execution of this protocol, please refer to Huang et al. (2020). Protective cutting method of the adult brain to minimize neural cell damages Co-culture system to study communications between different brain areas Monitoring circadian oscillations in non-SCN brain areas
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Affiliation(s)
- Suihong Huang
- Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, China
| | - Qingqing Lu
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Ming Ho Choi
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Xuebing Zhang
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Jin Young Kim
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.,Shenzhen Research Institute, City University of Hong Kong, Shenzhen, China
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In Vivo Simultaneous Analysis of Gene Expression by Dual-Color Luciferases in Caenorhabditis elegans. Int J Mol Sci 2020; 22:ijms22010119. [PMID: 33374403 PMCID: PMC7795788 DOI: 10.3390/ijms22010119] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 11/17/2022] Open
Abstract
Both fluorescent and luminescent observation are widely used to examine real-time gene expression patterns in living organisms. Several fluuorescent and luminescent proteins with specific optical properties have been developed and applied for simultaneous, multi-color observation of more than two gene expression profiles. Compared to fluorescent proteins, however, the application of multi-color luminescent imaging in living organisms is still limited. In this study, we introduced two-color luciferases into the soil nematode C. elegans and performed simultaneous analysis of two gene expression profiles. Using a green-emitting luciferase Eluc (emerald luciferase) and red-emitting luciferase SLR (stable luciferase red), the expression patterns of two genes were simultaneously observed in single animals from embryonic to adult stages over its whole life span. In addition, dual gene activities were observed at the single embryo level, with the simultaneous observation of morphological changes. These are the first application of a two-color luciferase system into a whole animal and suggest that precise relationship of expression patterns of multiple genes of interest can be analyzed over the whole life of the animal, dependent on the changes in genetic and/or environmental conditions.
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10
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Whitfield SJ, Padgen DB, Knight S, Gwyther RJ, Holley JL, Clark GC, Green AC. Establishment of a Novel Oral Murine Model of Ricin Intoxication and Efficacy Assessment of Ovine Ricin Antitoxins. Toxins (Basel) 2020; 12:E784. [PMID: 33302573 PMCID: PMC7764460 DOI: 10.3390/toxins12120784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/25/2020] [Accepted: 12/04/2020] [Indexed: 11/25/2022] Open
Abstract
Ricin, produced from the castor beans of Ricinus communis, is a cytotoxin that exerts its action by inactivating ribosomes and causing cell death. Accidental (e.g., ingestion of castor beans) and/or intentional (e.g., suicide) exposure to ricin through the oral route is an area of concern from a public health perspective and no current licensed medical interventions exist to protect from the action of the toxin. Therefore, we examined the oral toxicity of ricin in Balb/C mice and developed a robust food deprivation model of ricin oral intoxication that has enabled the assessment of potential antitoxin treatments. A lethal oral dose was identified and mice were found to succumb to the toxin within 48 h of exposure. We then examined whether a despeciated ovine F(ab')2 antibody fragment, that had previously been demonstrated to protect mice from exposure to aerosolised ricin, could also protect against oral intoxication. Mice were challenged orally with an LD99 of ricin, and 89 and 44% of mice exposed to this otherwise lethal exposure survived after receiving either the parent anti-ricin IgG or F(ab')2, respectively. Combined with our previous work, these results further highlight the benefit of ovine-derived polyclonal antibody antitoxin in providing post-exposure protection against ricin intoxication.
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Affiliation(s)
- Sarah J. Whitfield
- CBR Division, Dstl-Porton Down, Salisbury SP4 0JQ, UK; (D.B.P.); (S.K.); (R.J.G.); (J.L.H.); (G.C.C.); (A.C.G.)
| | - Debbie B. Padgen
- CBR Division, Dstl-Porton Down, Salisbury SP4 0JQ, UK; (D.B.P.); (S.K.); (R.J.G.); (J.L.H.); (G.C.C.); (A.C.G.)
| | - Simon Knight
- CBR Division, Dstl-Porton Down, Salisbury SP4 0JQ, UK; (D.B.P.); (S.K.); (R.J.G.); (J.L.H.); (G.C.C.); (A.C.G.)
| | - Robert J. Gwyther
- CBR Division, Dstl-Porton Down, Salisbury SP4 0JQ, UK; (D.B.P.); (S.K.); (R.J.G.); (J.L.H.); (G.C.C.); (A.C.G.)
| | - Jane L. Holley
- CBR Division, Dstl-Porton Down, Salisbury SP4 0JQ, UK; (D.B.P.); (S.K.); (R.J.G.); (J.L.H.); (G.C.C.); (A.C.G.)
| | - Graeme C. Clark
- CBR Division, Dstl-Porton Down, Salisbury SP4 0JQ, UK; (D.B.P.); (S.K.); (R.J.G.); (J.L.H.); (G.C.C.); (A.C.G.)
- Institute of Infection and Global Health, University of Liverpool, IC2 Building, Liverpool L3 5RF, UK
| | - A. Christopher Green
- CBR Division, Dstl-Porton Down, Salisbury SP4 0JQ, UK; (D.B.P.); (S.K.); (R.J.G.); (J.L.H.); (G.C.C.); (A.C.G.)
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11
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Hastings MH, Smyllie NJ, Patton AP. Molecular-genetic Manipulation of the Suprachiasmatic Nucleus Circadian Clock. J Mol Biol 2020; 432:3639-3660. [PMID: 31996314 DOI: 10.1016/j.jmb.2020.01.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 01/10/2020] [Accepted: 01/15/2020] [Indexed: 01/08/2023]
Abstract
Circadian (approximately daily) rhythms of physiology and behaviour adapt organisms to the alternating environments of day and night. The suprachiasmatic nucleus (SCN) of the hypothalamus is the principal circadian timekeeper of mammals. The mammalian cell-autonomous circadian clock is built around a self-sustaining transcriptional-translational negative feedback loop (TTFL) in which the negative regulators Per and Cry suppress their own expression, which is driven by the positive regulators Clock and Bmal1. Importantly, such TTFL-based clocks are present in all major tissues across the organism, and the SCN is their central co-ordinator. First, we analyse SCN timekeeping at the cell-autonomous and the circuit-based levels of organisation. We consider how molecular-genetic manipulations have been used to probe cell-autonomous timing in the SCN, identifying the integral components of the clock. Second, we consider new approaches that enable real-time monitoring of the activity of these clock components and clock-driven cellular outputs. Finally, we review how intersectional genetic manipulations of the cell-autonomous clockwork can be used to determine how SCN cells interact to generate an ensemble circadian signal. Critically, it is these network-level interactions that confer on the SCN its emergent properties of robustness, light-entrained phase and precision- properties that are essential for its role as the central co-ordinator. Remaining gaps in knowledge include an understanding of how the TTFL proteins behave individually and in complexes: whether particular SCN neuronal populations act as pacemakers, and if so, by which signalling mechanisms, and finally the nature of the recently discovered role of astrocytes within the SCN network.
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Affiliation(s)
- Michael H Hastings
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK.
| | - Nicola J Smyllie
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK
| | - Andrew P Patton
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK
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12
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Novel and Stable Dual-Color IL-6 and IL-10 Reporters Derived from RAW 264.7 for Anti-Inflammation Screening of Natural Products. Int J Mol Sci 2019; 20:ijms20184620. [PMID: 31540402 PMCID: PMC6769898 DOI: 10.3390/ijms20184620] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 02/07/2023] Open
Abstract
Our previous study suggested that the interleukin (IL)-6 and IL-10 could serve as good biomarkers for chronic inflammatory disease. We previously established an IL-6 and IL-10 reporters assay that could examine reporter activity along with the reference gene in LPS-induced RAW 264.7 cells. In this study, we described new and stable RAW 264.7 derived dual-color IL-6/gapdh and IL-10/gapdh reporters. This assay allowed us to easily determine relative IL-6 and IL-10 levels with 96-well plate within one step. We evaluated the relative IL-6 and IL-10 levels in the LPS-induced stable cells testing 52 natural products by real-time bioluminescence monitoring and time-point determination using a microplate luminometer. The relative IL-6 and IL-6/IL-10 values decreased by the crude ethanol extracts from nutmeg and by 1′S-1′-acetoxychavicol from greater galangal using real-time bioluminescence monitoring. At the same time, the relative IL-10 was induced. The relative IL-6 and IL-6/IL-10 decreased by crude ethanol extracts from nutmeg and 1′S-1′-acetoxychavicol acetate at 6 h. Only crude ethanol extract from nutmeg induced IL-10 at 6 h. We suggested that the use of these stable cells by real-time monitoring could serve as a screening assay for anti-inflammatory activity and may be used to discover new drugs against chronic inflammatory disease.
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13
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Sawai Y, Okamoto T, Muranaka Y, Nakamura R, Matsumura R, Node K, Akashi M. In vivo evaluation of the effect of lithium on peripheral circadian clocks by real-time monitoring of clock gene expression in near-freely moving mice. Sci Rep 2019; 9:10909. [PMID: 31358797 PMCID: PMC6662689 DOI: 10.1038/s41598-019-47053-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 07/01/2019] [Indexed: 01/31/2023] Open
Abstract
Lithium has been used as a mood stabilizer to treat human bipolar disorders for over half a century. Several studies have suggested the possibility that the efficacy of lithium treatment results in part from the amelioration of circadian dysfunction. However, the effect of lithium on clock gene expression has not yet been investigated in vivo because continuous measurement of gene expression in organs with high time resolution over a period of several days is difficult. To resolve this issue, we attached a small photo multiplier tube (PMT) tightly to the body surface of transgenic mice carrying a reporter gene such that the photon input window faced target organs such as the liver and kidney and succeeded in long-term continuous measurement of circadian gene expression in semi-freely moving mice over periods of several weeks. Using this simple method, we clearly showed that lithium causes circadian period elongation in peripheral clock gene expression rhythms in vivo. Further development of our detection system to maturity will aid a wide range of research fields in medicine and biology.
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Affiliation(s)
- Yuka Sawai
- The Research Institute for Time Studies, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8511, Japan
| | - Takezo Okamoto
- The Research Institute for Time Studies, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8511, Japan
| | - Yugo Muranaka
- The Research Institute for Time Studies, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8511, Japan
| | - Rino Nakamura
- The Research Institute for Time Studies, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8511, Japan
| | - Ritsuko Matsumura
- The Research Institute for Time Studies, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8511, Japan
| | - Koichi Node
- Department of Cardiovascular Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan
| | - Makoto Akashi
- The Research Institute for Time Studies, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8511, Japan.
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14
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Kleinovink JW, Mezzanotte L, Zambito G, Fransen MF, Cruz LJ, Verbeek JS, Chan A, Ossendorp F, Löwik C. A Dual-Color Bioluminescence Reporter Mouse for Simultaneous in vivo Imaging of T Cell Localization and Function. Front Immunol 2019; 9:3097. [PMID: 30671062 PMCID: PMC6333049 DOI: 10.3389/fimmu.2018.03097] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 12/13/2018] [Indexed: 12/16/2022] Open
Abstract
Non-invasive imaging technologies to visualize the location and functionality of T cells are of great value in immunology. Here, we describe the design and generation of a transgenic mouse in which all T cells constitutively express green-emitting click-beetle luciferase (CBG99) while expression of the red-emitting firefly luciferase (PpyRE9) is induced by Nuclear Factor of Activated T cells (NFAT) such as during T cell activation, which allows multicolor bioluminescence imaging of T cell location and function. This dual-luciferase mouse, which we named TbiLuc, showed high constitutive luciferase expression in lymphoid organs such as lymph nodes and the spleen. Ex vivo purified CD8+ and CD4+ T cells both constitutively expressed luciferase, whereas B cells showed no detectable signal. We cross-bred TbiLuc mice to T cell receptor-transgenic OT-I mice to obtain luciferase-expressing naïve CD8+ T cells with defined antigen-specificity. TbiLuc*OT-I T cells showed a fully antigen-specific induction of the T cell activation-dependent luciferase. In vaccinated mice, we visualized T cell localization and activation in vaccine-draining lymph nodes with high sensitivity using two distinct luciferase substrates, D-luciferin and CycLuc1, of which the latter specifically reacts with the PpyRE9 enzyme. This dual-luciferase T cell reporter mouse can be applied in many experimental models studying the location and functional state of T cells.
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Affiliation(s)
- Jan Willem Kleinovink
- Department of Immunohematology and Blood Transfusion, Tumor Immunology, Leiden University Medical Center, Leiden, Netherlands
| | - Laura Mezzanotte
- Department of Radiology and Nuclear Medicine, Optical Molecular Imaging, Erasmus Medical Center, Rotterdam, Netherlands.,Department of Molecular Genetics, Erasmus Medical Center Rotterdam, Netherlands
| | - Giorgia Zambito
- Department of Radiology and Nuclear Medicine, Optical Molecular Imaging, Erasmus Medical Center, Rotterdam, Netherlands.,Department of Molecular Genetics, Erasmus Medical Center Rotterdam, Netherlands.,Medres, Cologne, Germany
| | - Marieke F Fransen
- Department of Immunohematology and Blood Transfusion, Tumor Immunology, Leiden University Medical Center, Leiden, Netherlands
| | - Luis J Cruz
- Translational Nanobiomaterials and Imaging, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands
| | - J Sjef Verbeek
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Alan Chan
- Percuros B.V., Enschede, Netherlands
| | - Ferry Ossendorp
- Department of Immunohematology and Blood Transfusion, Tumor Immunology, Leiden University Medical Center, Leiden, Netherlands
| | - Clemens Löwik
- Department of Radiology and Nuclear Medicine, Optical Molecular Imaging, Erasmus Medical Center, Rotterdam, Netherlands.,Department of Molecular Genetics, Erasmus Medical Center Rotterdam, Netherlands.,Department of Oncology, CHUV Lausanne University Hospital, Lausanne, Switzerland
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15
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Saiki P, Nakajima Y, Van Griensven LJLD, Miyazaki K. Real-time monitoring of IL-6 and IL-10 reporter expression for anti-inflammation activity in live RAW 264.7 cells. Biochem Biophys Res Commun 2018; 505:885-890. [PMID: 30301531 DOI: 10.1016/j.bbrc.2018.09.173] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 09/27/2018] [Indexed: 11/29/2022]
Abstract
In previous study, we suggested that the interleukin (IL)-6 and IL-10 could serve as a good biomarker for anti-inflammation that related to chronic inflammatory disease. Recently, we are finding new anti-inflammation compounds from natural products by screening of IL-6 and IL-10 levels. Although, we could measure IL-6 and IL-10 levels by several methods. However, all methods could not measure continuous kinetic of IL-6 and IL-10 levels. Most methods have multiple steps and take a long time. Therefore, there is no a suitable method for screening. To this end, we established IL-6 and IL-10 promoter assay which can monitor with reference gene as Glyceraldehyde 3-phosphate dehydrogenase (gapdh) promoter in living single cell. It could determine IL-6 and IL-10 levels continuously in real-time within two steps. We evaluated IL-6 and IL-10 reporter expression in LPS-induced RAW 264.7 cells with well-known anti-inflammatory compounds such as quercetin, xanthones, β-D-glucan and dexamethasone. As the results, the expression of IL-6 and IL-10 reporters were strongly induced by LPS. The expression of IL-6 reporter was inhibited by all anti-inflammation compounds in LPS-induced RAW 264.7 cells. The expression of IL-10 reporter was inhibited by quercetin, xanthones and dexamethasone in LPS-induced RAW 264.7 cells. While, expression of IL-10 reporter was induced by β-D-glucan. These results indicated that this assay could use for determination of IL-6 and IL-10 reporter expression in LPS-induced RAW 264.7 cells for anti-inflammation activity. Moreover, the results showed that natural compounds have an effect on the time course of IL-6 and IL-10 expressions. Therefore, real-time monitoring has a merit for natural compounds screening. We suggested that this assay could serve as a compound screening assay for anti-inflammation activity.
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Affiliation(s)
- Papawee Saiki
- Biomedical Research Institute, National Institute of Advance Industrial Science and Technology, Tsukuba, Ibaraki, Japan.
| | - Yoshihiro Nakajima
- Health Research Institute, National Institute of Advance Industrial Science and Technology, Takamatsu, Kagawa, Japan
| | - Leo J L D Van Griensven
- Plant Research International, Wageningen University and Research Centre, Wageningen, the Netherlands
| | - Koyomi Miyazaki
- Biomedical Research Institute, National Institute of Advance Industrial Science and Technology, Tsukuba, Ibaraki, Japan
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16
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Nishide S, Honma S, Honma KI. Two coupled circadian oscillations regulate Bmal1-ELuc and Per2-SLR2 expression in the mouse suprachiasmatic nucleus. Sci Rep 2018; 8:14765. [PMID: 30283092 PMCID: PMC6170461 DOI: 10.1038/s41598-018-32516-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 08/01/2018] [Indexed: 11/08/2022] Open
Abstract
Circadian rhythms in clock genes, Bmal1 and Per2 expression were monitored simultaneously in the cultured slice of mouse suprachiasmatic nucleus (SCN) by dual bioluminescent reporters. In the neonatal SCN, the phase-relation between the Bmal1 and Per2 rhythms were significantly changed during culture. Medium exchange produced phase-dependent phase shifts (PRCm) in the Bmal1 rhythms, but not in the Per2 rhythms. As a result, the two circadian rhythms were temporally dissociated after medium exchange. In the adult SCN, the phase-relation between the two rhythms was kept constant during culture at least up to 20 cycles. The amplitude of PRCm in the adult SCN was significantly attenuated in the Bmal1 rhythm, whereas a PRCm was developed in the Per2 rhythm. The circadian period was not systematically affected by medium exchange in either of rhythms, regardless of whether it was in the neonatal or the adult SCN. Tetrodotoxin, a sodium channel blocker, enhanced the phase-response in both rhythms but abolished the phase-dependency. In addition, tetrodotoxin lengthened the circadian period independent of the phase of administration. Thus, the Bmal1 and Per2 rhythms in the SCN are dissociable and likely regulated by distinct circadian oscillators. Bmal1 is the component of a Bmal1/REV-ERBa/ROR loop and Per2 a Per/Cry/BMAL1/CLOCK loop. Both loops could be molecular mechanisms of the two circadian oscillators that are coupled through the protein product of Bmal1. The coupling strength between the two oscillations depends on developmental stages.
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Affiliation(s)
- Shinya Nishide
- Department of Physiology, Faculty of Medicine, Hokkaido University, Hokkaido, Japan
- Department of Occupational Therapy, School of Rehabilitation Science, Health Science University of Hokkaido, Hokkaido, Japan
| | - Sato Honma
- Research and Education Center for Brain Science, Hokkaido University, Hokkaido, Japan
| | - Ken-Ichi Honma
- Study Group for Monitoring of Brain Functions, Hokkaido University Graduate School of Medicine, Hokkaido, Japan.
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17
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Ishigami K, Furukawa H. Feature-preserving noise reduction by using time-domain Gaussian-weighted multiple noise reduction filters for real-time bioluminescence measurement. Anal Biochem 2018; 551:1-3. [PMID: 29727603 DOI: 10.1016/j.ab.2018.04.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 04/20/2018] [Accepted: 04/27/2018] [Indexed: 11/15/2022]
Abstract
This paper proposes a time-domain Gaussian-weighted noise reduction filter for bioluminescence measurement with low signal-to-noise ratio through photon counting. The filter was used for estimating the true fold-change signal from noisy gene expression data obtained through real-time dual-color luciferase assay. Furthermore, not only was the higher harmonics noise of the measurement system confirmed to reduce from the gene expression data but rapid and slow changes were also preserved in the estimated signal. In addition, the probability value of Pearson's chi-squared test was improved 257 times at most and 1.5 times on average without impairing the noise reduction ratio.
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Affiliation(s)
- Keisuke Ishigami
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan
| | - Hiromitsu Furukawa
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
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18
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Abstract
Mammalian circadian clocks have a hierarchical organization, governed by the suprachiasmatic nucleus (SCN) in the hypothalamus. The brain itself contains multiple loci that maintain autonomous circadian rhythmicity, but the contribution of the non-SCN clocks to this hierarchy remains unclear. We examine circadian oscillations of clock gene expression in various brain loci and discovered that in mouse, robust, higher amplitude, relatively faster oscillations occur in the choroid plexus (CP) compared to the SCN. Our computational analysis and modeling show that the CP achieves these properties by synchronization of “twist” circadian oscillators via gap-junctional connections. Using an in vitro tissue coculture model and in vivo targeted deletion of the Bmal1 gene to silence the CP circadian clock, we demonstrate that the CP clock adjusts the SCN clock likely via circulation of cerebrospinal fluid, thus finely tuning behavioral circadian rhythms. The suprachiasmatic nucleus (SCN) has been thought of as the master circadian clock, but peripheral circadian clocks do exist. Here, the authors show that the choroid plexus displays oscillations more robust than the SCN and that can be described as a Poincaré oscillator with negative twist.
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19
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Satoh D, Abe S, Kobayashi K, Nakajima Y, Oshimura M, Kazuki Y. Human and mouse artificial chromosome technologies for studies of pharmacokinetics and toxicokinetics. Drug Metab Pharmacokinet 2018; 33:17-30. [DOI: 10.1016/j.dmpk.2018.01.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/29/2017] [Accepted: 12/21/2017] [Indexed: 12/27/2022]
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20
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Mie Y, Hirano Y, Kowata K, Nakamura A, Yasunaga M, Nakajima Y, Komatsu Y. Function Control of Anti-microRNA Oligonucleotides Using Interstrand Cross-Linked Duplexes. MOLECULAR THERAPY. NUCLEIC ACIDS 2017; 10:64-74. [PMID: 29499957 PMCID: PMC5734696 DOI: 10.1016/j.omtn.2017.11.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 11/08/2017] [Accepted: 11/08/2017] [Indexed: 12/11/2022]
Abstract
MicroRNA (miRNA)-guided argonaute (Ago) controls gene expression upon binding to the 3′ UTR of mRNA. The miRNA function can be competitively inhibited by single-stranded anti-miRNA oligonucleotides (AMOs). In this study, we constructed a novel type of AMO flanked by interstrand cross-linked 2′-O-methylated RNA duplexes (CLs) that confer a stable helical conformation. Compared with other structured AMOs, AMO flanked by CLs at the 5′ and 3′ termini exhibited much higher inhibitory activity in cells. Anti-miRNA activity, nuclease resistance, and miRNA modification pattern distinctly differed according to the CL-connected positions in AMOs. Moreover, we found that the 3′-side CL improves nuclease resistance, whereas the 5′-side CL contributes to stable binding with miRNA in Ago upon interaction with the 3′ part of miRNA. These structure-function relationship analyses of AMOs provide important insights into the function control of Ago-miRNA complexes, which will be useful for basic miRNA research as well as for determining therapeutic applications of AMO.
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Affiliation(s)
- Yasuhiro Mie
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan
| | - Yu Hirano
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan
| | - Keiko Kowata
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan
| | - Akiyoshi Nakamura
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan
| | - Mayu Yasunaga
- Health Research Institute, AIST, 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Yoshihiro Nakajima
- Health Research Institute, AIST, 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Yasuo Komatsu
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan.
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21
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Tarnow P, Bross S, Wollenberg L, Nakajima Y, Ohmiya Y, Tralau T, Luch A. A Novel Dual-Color Luciferase Reporter Assay for Simultaneous Detection of Estrogen and Aryl Hydrocarbon Receptor Activation. Chem Res Toxicol 2017; 30:1436-1447. [DOI: 10.1021/acs.chemrestox.7b00076] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Patrick Tarnow
- German Federal Institute for Risk Assessment, Department
of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Steffi Bross
- German Federal Institute for Risk Assessment, Department
of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Lisa Wollenberg
- German Federal Institute for Risk Assessment, Department
of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Yoshihiro Nakajima
- Health
Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Yoshihiro Ohmiya
- DAILAB,
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Tewes Tralau
- German Federal Institute for Risk Assessment, Department
of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Andreas Luch
- German Federal Institute for Risk Assessment, Department
of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
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22
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Tabei Y, Murotomi K, Umeno A, Horie M, Tsujino Y, Masutani B, Yoshida Y, Nakajima Y. Antioxidant properties of 5-hydroxy-4-phenyl-butenolide via activation of Nrf2/ARE signaling pathway. Food Chem Toxicol 2017; 107:129-137. [PMID: 28655653 DOI: 10.1016/j.fct.2017.06.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 06/21/2017] [Accepted: 06/22/2017] [Indexed: 12/30/2022]
Abstract
5-Hydroxy-4-phenyl-butenolide (5H4PB) is a bioactive compound with antifungal and anti-obesity properties. Although it has recently been shown that 5H4PB activates peroxisome proliferator-activated receptor-gamma (PPARγ), the effect of 5H4PB on intracellular signaling pathways has not been clarified. In this study, we found that 5H4PB activated the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway, which plays an important role in cellular defense against oxidative stress, and the subsequent upregulation of ARE-dependent cytoprotective genes, including the heme oxygenase-1, catalase, and superoxide dismutase genes, without exhibiting cytotoxicity. In addition, 5H4PB significantly attenuated intracellular ROS generation, glutathione oxidation, and DNA damage induced by hydrogen peroxide (H2O2) exposure in mouse fibroblast cells. Furthermore, we demonstrated that pretreatment with 5H4PB confers a significant cytoprotective effect against H2O2-induced cell death in mouse cultured fibroblasts and primary hepatocytes. Thus, our study demonstrated that 5H4PB enhanced cellular resistance to oxidative damage via activation of the Nrf2/ARE signaling pathway.
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Affiliation(s)
- Yosuke Tabei
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Kazutoshi Murotomi
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Aya Umeno
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Masanori Horie
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Yoshio Tsujino
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Bumbu Masutani
- Kojun Japan Co., Ltd., 1-5-20 Tenma, Kita-ku, Osaka 530-0043, Japan
| | - Yasukazu Yoshida
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Yoshihiro Nakajima
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan.
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Ono D, Honma S, Nakajima Y, Kuroda S, Enoki R, Honma KI. Dissociation of Per1 and Bmal1 circadian rhythms in the suprachiasmatic nucleus in parallel with behavioral outputs. Proc Natl Acad Sci U S A 2017; 114:E3699-E3708. [PMID: 28416676 PMCID: PMC5422828 DOI: 10.1073/pnas.1613374114] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The temporal order of physiology and behavior in mammals is primarily regulated by the circadian pacemaker located in the hypothalamic suprachiasmatic nucleus (SCN). Taking advantage of bioluminescence reporters, we monitored the circadian rhythms of the expression of clock genes Per1 and Bmal1 in the SCN of freely moving mice and found that the rate of phase shifts induced by a single light pulse was different in the two rhythms. The Per1-luc rhythm was phase-delayed instantaneously by the light presented at the subjective evening in parallel with the activity onset of behavioral rhythm, whereas the Bmal1-ELuc rhythm was phase-delayed gradually, similar to the activity offset. The dissociation was confirmed in cultured SCN slices of mice carrying both Per1-luc and Bmal1-ELuc reporters. The two rhythms in a single SCN slice showed significantly different periods in a long-term (3 wk) culture and were internally desynchronized. Regional specificity in the SCN was not detected for the period of Per1-luc and Bmal1-ELuc rhythms. Furthermore, neither is synchronized with circadian intracellular Ca2+ rhythms monitored by a calcium indicator, GCaMP6s, or with firing rhythms monitored on a multielectrode array dish, although the coupling between the circadian firing and Ca2+ rhythms persisted during culture. These findings indicate that the expressions of two key clock genes, Per1 and Bmal1, in the SCN are regulated in such a way that they may adopt different phases and free-running periods relative to each other and are respectively associated with the expression of activity onset and offset.
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Affiliation(s)
- Daisuke Ono
- Photonic Bioimaging Section, Research Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan;
| | - Sato Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan;
| | - Yoshihiro Nakajima
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | - Shigeru Kuroda
- Research Institute for Electronic Science, Hokkaido University, Sapporo, 001-0020, Japan
| | - Ryosuke Enoki
- Photonic Bioimaging Section, Research Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Ken-Ichi Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
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24
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Wakuri S, Yamakage K, Kazuki Y, Kazuki K, Oshimura M, Aburatani S, Yasunaga M, Nakajima Y. Correlation between luminescence intensity and cytotoxicity in cell-based cytotoxicity assay using luciferase. Anal Biochem 2017; 522:18-29. [PMID: 28111305 DOI: 10.1016/j.ab.2017.01.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 01/17/2017] [Accepted: 01/18/2017] [Indexed: 10/20/2022]
Abstract
The luciferase reporter assay has become one of the conventional methods for cytotoxicity evaluation. Typically, the decrease of luminescence expressed by a constitutive promoter is used as an index of cytotoxicity. However, to our knowledge, there have been no reports of the correlation between cytotoxicity and luminescence intensity. In this study, to accurately verify the correlation between them, beetle luciferase was stably expressed in human hepatoma HepG2 cells harboring the multi-integrase mouse artificial chromosome vector. We showed that the cytotoxicity assay using luciferase does not depend on the stability of luciferase protein and the kind of constitutive promoter. Next, HepG2 cells in which green-emitting beetle luciferase was expressed under the control of CAG promoter were exposed to 58 compounds. The luminescence intensity and cytotoxicity curves of cells exposed to 48 compounds showed similar tendencies, whereas those of cells exposed to 10 compounds did not do so, although the curves gradually approached each other with increasing exposure time. Finally, we demonstrated that luciferase expressed under the control of a constitutive promoter can be utilized both as an internal control reporter for normalizing a test reporter and for monitoring cytotoxicity when two kinds of luciferases are simultaneously used in the cytotoxicity assay.
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Affiliation(s)
- S Wakuri
- Hatano Research Institute, Food and Drug Safety Center, Hadano, Kanagawa 257-8523, Japan
| | - K Yamakage
- Hatano Research Institute, Food and Drug Safety Center, Hadano, Kanagawa 257-8523, Japan
| | - Y Kazuki
- Chromosome Engineering Research Center, Tottori University, Yonago, Tottori 683-8503, Japan; Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Tottori 683-8503, Japan
| | - K Kazuki
- Chromosome Engineering Research Center, Tottori University, Yonago, Tottori 683-8503, Japan
| | - M Oshimura
- Chromosome Engineering Research Center, Tottori University, Yonago, Tottori 683-8503, Japan
| | - S Aburatani
- Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), Aomi, Tokyo 135-0064, Japan
| | - M Yasunaga
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | - Y Nakajima
- Chromosome Engineering Research Center, Tottori University, Yonago, Tottori 683-8503, Japan; Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan.
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25
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Herzog ED, Hermanstyne T, Smyllie NJ, Hastings MH. Regulating the Suprachiasmatic Nucleus (SCN) Circadian Clockwork: Interplay between Cell-Autonomous and Circuit-Level Mechanisms. Cold Spring Harb Perspect Biol 2017; 9:9/1/a027706. [PMID: 28049647 DOI: 10.1101/cshperspect.a027706] [Citation(s) in RCA: 149] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The suprachiasmatic nucleus (SCN) is the principal circadian clock of the brain, directing daily cycles of behavior and physiology. SCN neurons contain a cell-autonomous transcription-based clockwork but, in turn, circuit-level interactions synchronize the 20,000 or so SCN neurons into a robust and coherent daily timer. Synchronization requires neuropeptide signaling, regulated by a reciprocal interdependence between the molecular clockwork and rhythmic electrical activity, which in turn depends on a daytime Na+ drive and nighttime K+ drag. Recent studies exploiting intersectional genetics have started to identify the pacemaking roles of particular neuronal groups in the SCN. They support the idea that timekeeping involves nonlinear and hierarchical computations that create and incorporate timing information through the interactions between key groups of neurons within the SCN circuit. The field is now poised to elucidate these computations, their underlying cellular mechanisms, and how the SCN clock interacts with subordinate circadian clocks across the brain to determine the timing and efficiency of the sleep-wake cycle, and how perturbations of this coherence contribute to neurological and psychiatric illness.
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Affiliation(s)
- Erik D Herzog
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri 63130-4899
| | - Tracey Hermanstyne
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri 63130-4899
| | - Nicola J Smyllie
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Michael H Hastings
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
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26
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Evans JA. Collective timekeeping among cells of the master circadian clock. J Endocrinol 2016; 230:R27-49. [PMID: 27154335 PMCID: PMC4938744 DOI: 10.1530/joe-16-0054] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/06/2016] [Indexed: 01/09/2023]
Abstract
The suprachiasmatic nucleus (SCN) of the anterior hypothalamus is the master circadian clock that coordinates daily rhythms in behavior and physiology in mammals. Like other hypothalamic nuclei, the SCN displays an impressive array of distinct cell types characterized by differences in neurotransmitter and neuropeptide expression. Individual SCN neurons and glia are able to display self-sustained circadian rhythms in cellular function that are regulated at the molecular level by a 24h transcriptional-translational feedback loop. Remarkably, SCN cells are able to harmonize with one another to sustain coherent rhythms at the tissue level. Mechanisms of cellular communication in the SCN network are not completely understood, but recent progress has provided insight into the functional roles of several SCN signaling factors. This review discusses SCN organization, how intercellular communication is critical for maintaining network function, and the signaling mechanisms that play a role in this process. Despite recent progress, our understanding of SCN circuitry and coupling is far from complete. Further work is needed to map SCN circuitry fully and define the signaling mechanisms that allow for collective timekeeping in the SCN network.
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Affiliation(s)
- Jennifer A Evans
- Department of Biomedical SciencesMarquette University, Milwaukee, WI, USA
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27
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Nishiguchi T, Yamada T, Nasu Y, Ito M, Yoshimura H, Ozawa T. Development of red-shifted mutants derived from luciferase of Brazilian click beetle Pyrearinus termitilluminans. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:101205. [PMID: 26313214 DOI: 10.1117/1.jbo.20.10.101205] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 07/31/2015] [Indexed: 06/04/2023]
Abstract
Luciferase, a bioluminescent protein, has been used as an analytical tool to visualize intracellular phenomena. Luciferase with red light emission is particularly useful for bioluminescence imaging because of its high transmittance in mammalian tissues. However, the luminescence intensity of existing luciferases with their emission over 600 nm is insufficient for imaging studies because of their weak intensities. We developed mutants of Emerald luciferase (Eluc) from Brazilian click beetle (Pyrearinus termitilluminans), which emits the strongest bioluminescence among beetle luciferases. We successively introduced four amino acid mutations into the luciferase based on a predicted structure of Eluc using homology modeling. Results showed that quadruple mutations R214K/H241K/S246H/H347A into the beetle luciferase emit luminescence with emission maximum at 626 nm, 88-nm red-shift from the wild-type luciferase. This mutant luciferase is anticipated for application in in vivo multicolor imaging in living samples.
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28
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Ono D, Honma KI, Honma S. Circadian and ultradian rhythms of clock gene expression in the suprachiasmatic nucleus of freely moving mice. Sci Rep 2015; 5:12310. [PMID: 26194231 PMCID: PMC4508664 DOI: 10.1038/srep12310] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 06/25/2015] [Indexed: 11/09/2022] Open
Abstract
In mammals, the temporal order of physiology and behavior is primarily regulated by the circadian pacemaker located in the hypothalamic suprachiasmatic nucleus (SCN). Rhythms are generated in cells by an auto-regulatory transcription/translation feedback loop, composed of several clock genes and their protein products. Taking advantage of bioluminescence reporters, we have succeeded in continuously monitoring the expression of clock gene reporters Per1-luc, PER2::LUC and Bmal1-ELuc in the SCN of freely moving mice for up to 3 weeks in constant darkness. Bioluminescence emitted from the SCN was collected with an implanted plastic optical fiber which was connected to a cooled photomultiplier tube. We found robust circadian rhythms in the clock gene expression, the phase-relation of which were the same as those observed ex vivo. The circadian rhythms were superimposed by episodic bursts which had ultradian periods of approximately 3.0 h. Episodic bursts often accompanied activity bouts, but stoichiometric as well as temporal analyses revealed no causality between them. Clock gene expression in the SCN in vivo is regulated by the circadian pacemaker and ultradian rhythms of unknown origin.
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Affiliation(s)
- Daisuke Ono
- Photonic Bioimaging Section, Research Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
| | - Ken-ichi Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
| | - Sato Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
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29
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Myung J, Hong S, DeWoskin D, De Schutter E, Forger DB, Takumi T. GABA-mediated repulsive coupling between circadian clock neurons in the SCN encodes seasonal time. Proc Natl Acad Sci U S A 2015; 112:E3920-9. [PMID: 26130804 PMCID: PMC4517217 DOI: 10.1073/pnas.1421200112] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The mammalian suprachiasmatic nucleus (SCN) forms not only the master circadian clock but also a seasonal clock. This neural network of ∼10,000 circadian oscillators encodes season-dependent day-length changes through a largely unknown mechanism. We show that region-intrinsic changes in the SCN fine-tune the degree of network synchrony and reorganize the phase relationship among circadian oscillators to represent day length. We measure oscillations of the clock gene Bmal1, at single-cell and regional levels in cultured SCN explanted from animals raised under short or long days. Coupling estimation using the Kuramoto framework reveals that the network has couplings that can be both phase-attractive (synchronizing) and -repulsive (desynchronizing). The phase gap between the dorsal and ventral regions increases and the overall period of the SCN shortens with longer day length. We find that one of the underlying physiological mechanisms is the modulation of the intracellular chloride concentration, which can adjust the strength and polarity of the ionotropic GABAA-mediated synaptic input. We show that increasing day-length changes the pattern of chloride transporter expression, yielding more excitatory GABA synaptic input, and that blocking GABAA signaling or the chloride transporter disrupts the unique phase and period organization induced by the day length. We test the consequences of this tunable GABA coupling in the context of excitation-inhibition balance through detailed realistic modeling. These results indicate that the network encoding of seasonal time is controlled by modulation of intracellular chloride, which determines the phase relationship among and period difference between the dorsal and ventral SCN.
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Affiliation(s)
- Jihwan Myung
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan; Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Sungho Hong
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495, Japan
| | - Daniel DeWoskin
- Department of Mathematics, University of Michigan, Ann Arbor, MI 48109
| | - Erik De Schutter
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495, Japan
| | - Daniel B Forger
- Department of Mathematics, University of Michigan, Ann Arbor, MI 48109; Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109
| | - Toru Takumi
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan; Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo 102-0076, Japan
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30
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Yasunaga M, Nakajima Y, Ohmiya Y. Dual-color bioluminescence imaging assay using green- and red-emitting beetle luciferases at subcellular resolution. Anal Bioanal Chem 2015; 406:5735-42. [PMID: 25015042 DOI: 10.1007/s00216-014-7981-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 06/09/2014] [Accepted: 06/16/2014] [Indexed: 11/28/2022]
Abstract
Bioluminescence imaging is widely used to monitor cellular events, including gene expression in vivo and in vitro. Moreover, recent advances in luciferase technology have made possible imaging at the single-cell level. To improve the bioluminescence imaging system, we have developed a dual-color imaging system in which the green-emitting luciferase from a Brazilian click beetle (Emerald Luc, ELuc) and the red-emitting luciferase from a railroad worm (Stable Luciferase Red, SLR) were used as reporters, which were localized to the peroxisome and the nucleus, respectively. We clearly captured simultaneously the subcellular localization of ELuc in the peroxisome and SLR in the nucleus of a single cell using a high-magnification objective lens with 3-min exposure time without binning using a combination of optical filters. Furthermore, to apply this system to quantitative time-lapse imaging, the activation of nuclear factor triggered by tumor necrosis factor α was measured using nuclear-targeted SLR and peroxisome-targeted ELuc as the test and internal control reporters, respectively. We successfully quantified the kinetics of activation of nuclear factor κB using nuclear-targeted SLR and the transcriptional change of the internal control promoter using peroxisome-targeted ELuc simultaneously in a single cell, and showed that the activation kinetics, including activation rate and amplitude, differed among cells. The results demonstrated that this imaging system can visualize the subcellular localization of reporters and track the expressions of two genes simultaneously at subcellular resolution.
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31
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Abstract
Fasting of mice is a common procedure performed in association with many different types of experiments mainly in order to reduce variability in investigatory parameters or to facilitate surgical procedures. However, the effects of fasting not directly related to the investigatory parameters are often ignored. The aim of this review is to present and summarize knowledge about the effects of fasting of mice to facilitate optimization of the fasting procedure for any given study and thereby maximize the scientific outcome and minimize the discomfort for the mice and hence ensure high animal welfare. The results are presented from a number of experimental studies, providing evidence for fasting-induced changes in hormone balance, body weight, metabolism, hepatic enzymes, cardiovascular parameters, body temperature and toxicological responses. A description of relevant normal behaviour and standard physiological parameters is given, concluding that mice are primarily nocturnal and consume two-thirds of their total food intake during the night. It is argued that overnight fasting of mice is not comparable with overnight fasting of humans because the mouse has a nocturnal circadian rhythm and a higher metabolic rate. It is suggested that because many physiological parameters are regulated by circadian rhythms, fasting initiated at different points in the circadian rhythm has different impacts and produces different results.
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Affiliation(s)
- T L Jensen
- Novo Nordisk, Animal Unit, Maaloev, Denmark
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32
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In vitro circadian period is associated with circadian/sleep preference. Sci Rep 2013; 3:2074. [PMID: 23797865 PMCID: PMC3691610 DOI: 10.1038/srep02074] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 06/07/2013] [Indexed: 11/24/2022] Open
Abstract
Evaluation of circadian phenotypes is crucial for understanding the pathophysiology of diseases associated with disturbed biological rhythms such as circadian rhythm sleep disorders (CRSDs). We measured clock gene expression in fibroblasts from individual subjects and observed circadian rhythms in the cells (in vitro rhythms). Period length of the in vitro rhythm (in vitro period) was compared with the intrinsic circadian period, τ, measured under a forced desynchrony protocol (in vivo period) and circadian/sleep parameters evaluated by questionnaires, sleep log, and actigraphy. Although no significant correlation was observed between the in vitro and in vivo periods, the in vitro period was correlated with chronotype, habitual sleep time, and preferred sleep time. Our data demonstrate that the in vitro period is significantly correlated with circadian/sleep preference. The findings suggest that fibroblasts from individual patients can be utilized for in vitro screening of therapeutic agents to provide personalized therapeutic regimens for CRSD patients.
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33
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Sandu C, Dumas M, Malan A, Sambakhe D, Marteau C, Nizard C, Schnebert S, Perrier E, Challet E, Pévet P, Felder-Schmittbuhl MP. Human skin keratinocytes, melanocytes, and fibroblasts contain distinct circadian clock machineries. Cell Mol Life Sci 2012; 69:3329-39. [PMID: 22627494 PMCID: PMC11114759 DOI: 10.1007/s00018-012-1026-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 05/02/2012] [Accepted: 05/03/2012] [Indexed: 12/22/2022]
Abstract
Skin acts as a barrier between the environment and internal organs and performs functions that are critical for the preservation of body homeostasis. In mammals, a complex network of circadian clocks and oscillators adapts physiology and behavior to environmental changes by generating circadian rhythms. These rhythms are induced in the central pacemaker and peripheral tissues by similar transcriptional-translational feedback loops involving clock genes. In this work, we investigated the presence of functional oscillators in the human skin by studying kinetics of clock gene expression in epidermal and dermal cells originating from the same donor and compared their characteristics. Primary cultures of fibroblasts, keratinocytes, and melanocytes were established from an abdominal biopsy and expression of clock genes following dexamethasone synchronization was assessed by qPCR. An original mathematical method was developed to analyze simultaneously up to nine clock genes. By fitting the oscillations to a common period, the phase relationships of the genes could be determined accurately. We thereby show the presence of functional circadian machinery in each cell type. These clockworks display specific periods and phase relationships between clock genes, suggesting regulatory mechanisms that are particular to each cell type. Taken together, our data demonstrate that skin has a complex circadian organization. Oscillators are present not only in fibroblasts but also in epidermal keratinocytes and melanocytes and are likely to act in coordination to drive rhythmic functions within the skin.
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Affiliation(s)
- Cristina Sandu
- Department of Neurobiology of Rhythms, Institute of Cellular and Integrative Neurosciences, CNRS UPR 3212, 5 rue Blaise Pascal, 67084 Strasbourg, France
| | - Marc Dumas
- LVMH Recherche, 185 avenue de Verdun, 45804 Saint Jean de Braye Cedex, France
| | - André Malan
- Department of Neurobiology of Rhythms, Institute of Cellular and Integrative Neurosciences, CNRS UPR 3212, 5 rue Blaise Pascal, 67084 Strasbourg, France
| | - Diariétou Sambakhe
- Department of Neurobiology of Rhythms, Institute of Cellular and Integrative Neurosciences, CNRS UPR 3212, 5 rue Blaise Pascal, 67084 Strasbourg, France
- Unit of Mathematics and Computer Science, University of Strasbourg, 7 rue René Descartes, 67084 Strasbourg, France
| | - Clarisse Marteau
- LVMH Recherche, 185 avenue de Verdun, 45804 Saint Jean de Braye Cedex, France
| | - Carine Nizard
- LVMH Recherche, 185 avenue de Verdun, 45804 Saint Jean de Braye Cedex, France
| | - Sylvianne Schnebert
- LVMH Recherche, 185 avenue de Verdun, 45804 Saint Jean de Braye Cedex, France
| | - Eric Perrier
- LVMH Recherche, 185 avenue de Verdun, 45804 Saint Jean de Braye Cedex, France
| | - Etienne Challet
- Department of Neurobiology of Rhythms, Institute of Cellular and Integrative Neurosciences, CNRS UPR 3212, 5 rue Blaise Pascal, 67084 Strasbourg, France
| | - Paul Pévet
- Department of Neurobiology of Rhythms, Institute of Cellular and Integrative Neurosciences, CNRS UPR 3212, 5 rue Blaise Pascal, 67084 Strasbourg, France
| | - Marie-Paule Felder-Schmittbuhl
- Department of Neurobiology of Rhythms, Institute of Cellular and Integrative Neurosciences, CNRS UPR 3212, 5 rue Blaise Pascal, 67084 Strasbourg, France
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34
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Myung J, Hong S, Hatanaka F, Nakajima Y, De Schutter E, Takumi T. Period coding of Bmal1 oscillators in the suprachiasmatic nucleus. J Neurosci 2012; 32:8900-18. [PMID: 22745491 PMCID: PMC6622328 DOI: 10.1523/jneurosci.5586-11.2012] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Revised: 05/02/2012] [Accepted: 05/05/2012] [Indexed: 01/12/2023] Open
Abstract
Circadian oscillators in the suprachiasmatic nucleus (SCN) collectively orchestrate 24 h rhythms in the body while also coding for seasonal rhythms. Although synchronization is required among SCN oscillators to provide robustness for regular timekeeping (Herzog et al., 2004), heterogeneity of period and phase distributions is needed to accommodate seasonal variations in light duration (Pittendrigh and Daan, 1976b). In the mouse SCN, the heterogeneous phase distribution has been recently found in the cycling of clock genes Period 1 and Period 2 (Per1, Per2) and has been shown to reorganize by relative day lengths (Inagaki et al., 2007). However, it is not yet clearly understood what underlies the spatial patterning of Per1 and Per2 expression (Yamaguchi et al., 2003; Foley et al., 2011) and its plasticity. We found that the period of the oscillation in Bmal1 expression, a positive-feedback component of the circadian clock, preserves the behavioral circadian period under culture and drives clustered oscillations in the mouse SCN. Pharmacological and physical isolations of SCN subregions indicate that the period of Bmal1 oscillation is subregion specific and is preserved during culture. Together with computer simulations, we show that either the intercellular coupling does not strongly influence the Bmal1 oscillation or the nature of the coupling is more complex than previously assumed. Furthermore, we have found that the region-specific periods are modulated by the light conditions that an animal is exposed to. Based on these, we suggest that the period forms the basis of seasonal coding in the SCN.
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Affiliation(s)
- Jihwan Myung
- Osaka Bioscience Institute, Suita, Osaka 565-0874, Japan
- Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto 606-8501, Japan
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Sungho Hong
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0411, Japan
| | - Fumiyuki Hatanaka
- Osaka Bioscience Institute, Suita, Osaka 565-0874, Japan
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Yoshihiro Nakajima
- National Institute of Advanced Industrial Science and Technology, Takamatsu, Kagawa 761-0395, Japan
| | - Erik De Schutter
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0411, Japan
- Theoretical Neurobiology, University of Antwerp, B-2610 Antwerp, Belgium, and
| | - Toru Takumi
- Osaka Bioscience Institute, Suita, Osaka 565-0874, Japan
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo 102-0076, Japan
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35
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Tahara Y, Kuroda H, Saito K, Nakajima Y, Kubo Y, Ohnishi N, Seo Y, Otsuka M, Fuse Y, Ohura Y, Komatsu T, Moriya Y, Okada S, Furutani N, Hirao A, Horikawa K, Kudo T, Shibata S. In vivo monitoring of peripheral circadian clocks in the mouse. Curr Biol 2012; 22:1029-34. [PMID: 22578421 DOI: 10.1016/j.cub.2012.04.009] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 03/22/2012] [Accepted: 04/04/2012] [Indexed: 10/28/2022]
Abstract
The mammalian circadian system is comprised of a central clock in the suprachiasmatic nucleus (SCN) and a network of peripheral oscillators located in all of the major organ systems. The SCN is traditionally thought to be positioned at the top of the hierarchy, with SCN lesions resulting in an arrhythmic organism. However, recent work has demonstrated that the SCN and peripheral tissues generate independent circadian oscillations in Per1 clock gene expression in vitro. In the present study, we sought to clarify the role of the SCN in the intact system by recording rhythms in clock gene expression in vivo. A practical imaging protocol was developed that enables us to measure circadian rhythms easily, noninvasively, and longitudinally in individual mice. Circadian oscillations were detected in the kidney, liver, and submandibular gland studied in about half of the SCN-lesioned, behaviorally arrhythmic mice. However, their amplitude was decreased in these organs. Free-running periods of peripheral clocks were identical to those of activity rhythms recorded before the SCN lesion. Thus, we can report for the first time that many of the fundamental properties of circadian oscillations in peripheral clocks in vivo are maintained in the absence of SCN control.
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Affiliation(s)
- Yu Tahara
- Department of Physiology and Pharmacology, School of Advanced Science and Engineering, Waseda University, Tokyo 162-8480, Japan
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Noguchi T, Ikeda M, Ohmiya Y, Nakajima Y. A dual-color luciferase assay system reveals circadian resetting of cultured fibroblasts by co-cultured adrenal glands. PLoS One 2012; 7:e37093. [PMID: 22615906 PMCID: PMC3352896 DOI: 10.1371/journal.pone.0037093] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2012] [Accepted: 04/17/2012] [Indexed: 11/22/2022] Open
Abstract
In mammals, circadian rhythms of various organs and tissues are synchronized by pacemaker neurons in the suprachiasmatic nucleus (SCN) of the hypothalamus. Glucocorticoids released from the adrenal glands can synchronize circadian rhythms in other tissues. Many hormones show circadian rhythms in their plasma concentrations; however, whether organs outside the SCN can serve as master synchronizers to entrain circadian rhythms in target tissues is not well understood. To further delineate the function of the adrenal glands and the interactions of circadian rhythms in putative master synchronizing organs and their target tissues, here we report a simple co-culture system using a dual-color luciferase assay to monitor circadian rhythms separately in various explanted tissues and fibroblasts. In this system, circadian rhythms of organs and target cells were simultaneously tracked by the green-emitting beetle luciferase from Pyrearinus termitilluminans (ELuc) and the red-emitting beetle luciferase from Phrixothrix hirtus (SLR), respectively. We obtained tissues from the adrenal glands, thyroid glands, and lungs of transgenic mice that expressed ELuc under control of the promoter from a canonical clock gene, mBmal1. The tissues were co-cultured with Rat-1 fibroblasts as representative target cells expressing SLR under control of the mBmal1 promoter. Amplitudes of the circadian rhythms of Rat-1 fibroblasts were potentiated when the fibroblasts were co-cultured with adrenal gland tissue, but not when co-cultured with thyroid gland or lung tissue. The phases of Rat-1 fibroblasts were reset by application of adrenal gland tissue, whereas the phases of adrenal gland tissue were not influenced by Rat-1 fibroblasts. Furthermore, the effect of the adrenal gland tissue on the fibroblasts was blocked by application of a glucocorticoid receptor (GR) antagonist. These results demonstrate that glucocorticoids are strong circadian synchronizers for fibroblasts and that this co-culture system is a useful tool to analyze humoral communication between different tissues or cell populations.
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Affiliation(s)
- Takako Noguchi
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda, Osaka, Japan
| | - Masaaki Ikeda
- Molecular Clock Project, Research Center for Genomic Medicine, Saitama Medical University, Hidaka, Saitama, Japan
- Department of Physiology, Saitama Medical University, Moroyama, Saitama, Japan
| | - Yoshihiro Ohmiya
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Yoshihiro Nakajima
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda, Osaka, Japan
- * E-mail:
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Niu G, Chen X. Molecular imaging with activatable reporter systems. Am J Cancer Res 2012; 2:413-23. [PMID: 22539937 PMCID: PMC3337733 DOI: 10.7150/thno.3940] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Accepted: 02/08/2012] [Indexed: 12/28/2022] Open
Abstract
Molecular imaging is a newly emerged multiple disciplinary field that aims to visualize, characterize and quantitatively measure biological processes at cellular and molecular levels in humans and other living systems. A reporter gene is a piece of DNA encoding reporter protein, which presents as a readily measurable phenotype that can be distinguished easily from the background of endogenous protein. After being transferred into cells of organ systems (transgenes), the reporter gene can be utilized to visualize transcriptional and posttranscriptional regulation of gene expression, protein-protein interactions, or trafficking of proteins or cells in living subjects. Herein, we review previous classification of reporter genes and regroup the reporter gene based imaging as basic, inducible and activatable, based on the regulation of reporter gene transcription and post-translational modification of reporter proteins. We then focus on activatable reporters, in which the signal can be activated at the posttranslational level for visualizing protein-protein interactions, protein phosphorylation or tertiary structure changes. The applications of several types of activatable reporters will also be summarized. We conclude that activatable reporter imaging can benefit both basic biomedical research and drug development.
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Ebrahimi M, Hosseinkhani S, Heydari A, Khavari-Nejad RA, Akbari J. Controversial effect of two methylguanidine-based ionic liquids on firefly luciferase. Photochem Photobiol Sci 2012; 11:828-34. [DOI: 10.1039/c2pp05389f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
Humans and other mammals exhibit a remarkable array of cyclical changes in physiology and behaviour. These are often synchronized to the changing environmental light–dark cycle and persist in constant conditions. Such circadian rhythms are controlled by an endogenous clock, located in the suprachiasmatic nuclei of the hypothalamus. This structure and its cells have unique properties, and some of these are reviewed to highlight how this central clock controls and sculpts our daily activities.
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Sensitive dual color in vivo bioluminescence imaging using a new red codon optimized firefly luciferase and a green click beetle luciferase. PLoS One 2011; 6:e19277. [PMID: 21544210 PMCID: PMC3081340 DOI: 10.1371/journal.pone.0019277] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 03/30/2011] [Indexed: 02/05/2023] Open
Abstract
Background Despite a plethora of bioluminescent reporter genes being cloned and used for cell assays and molecular imaging purposes, the simultaneous monitoring of multiple events in small animals is still challenging. This is partly attributable to the lack of optimization of cell reporter gene expression as well as too much spectral overlap of the color-coupled reporter genes. A new red emitting codon-optimized luciferase reporter gene mutant of Photinus pyralis, Ppy RE8, has been developed and used in combination with the green click beetle luciferase, CBG99. Principal Findings Human embryonic kidney cells (HEK293) were transfected with vectors that expressed red Ppy RE8 and green CBG99 luciferases. Populations of red and green emitting cells were mixed in different ratios. After addition of the shared single substrate, D-luciferin, bioluminescent (BL) signals were imaged with an ultrasensitive cooled CCD camera using a series of band pass filters (20 nm). Spectral unmixing algorithms were applied to the images where good separation of signals was observed. Furthermore, HEK293 cells that expressed the two luciferases were injected at different depth in the animals. Spectrally-separate images and quantification of the dual BL signals in a mixed population of cells was achieved when cells were either injected subcutaneously or directly into the prostate. Significance We report here the re-engineering of different luciferase genes for in vitro and in vivo dual color imaging applications to address the technical issues of using dual luciferases for imaging. In respect to previously used dual assays, our study demonstrated enhanced sensitivity combined with spatially separate BL spectral emissions using a suitable spectral unmixing algorithm. This new D-luciferin-dependent reporter gene couplet opens up the possibility in the future for more accurate quantitative gene expression studies in vivo by simultaneously monitoring two events in real time.
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Abstract
Many biochemical events within a cell need to be timed properly to occur at specific times of day, after other events have happened within the cell or in response to environmental signals. The cellular biochemical feedback loops that time these events have already received much recent attention in the experimental and modeling communities. Here, we show how ideas from signal processing can be applied to understand the function of these clocks. Consider two signals from the network s(t) and r(t), either two variables of a model or two experimentally measured time courses. We show how s(t) can be decomposed into two parts, the first being a function of r(t), and the second the derivative of a function of r(t). Geometric principles are then derived that can be used to understand when oscillations appear in biochemical feedback loops, the period of these oscillations, and their time course. Specific examples of this theory are provided that show how certain networks are prone or not prone to oscillate, how individual biochemical processes affect the period, and how oscillations in one chemical species can be deduced from oscillations in other parts of the network.
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